#1. The server is always restarted with a warning. You probably were on when it crashes, and that is common for everyone to lose a car here and there....
#2. Either you are being disconnected while still on the track, and/or you are not reading the rules of the game to save your cars properly.....
#3. lol?
#4. The admins and 'friends' get back on the server because they were on their previously and are given a temporary password to reconnect so they wont lose their spot. Maybe you aren't paying attention to the password they hand out?